Orange Peel Derived Carbon Nanospheres Decorated By Manganese Oxide Nanosheets, Intercalated Into Polypyrrole, As an Inside-Needle Capillary Adsorption Trap Sorbent For Analysis Of Linear Alkylbenzenes

Carbon nanospheres (CNSs) were derived hydrothermally from biomass (orange peels) and decorated by manganese dioxide (MnO۲) nanosheets. The MnO۲/CNSs nanocomposite was intercalated into polypyrrole (PPy) during flow-through in-situ electropolymerization of pyrrole on the surface of the inner wall of a stainless-steel needle to preparing inside-needle capillary adsorption trap (INCAT) device. The surface morphology, sorption characteristics, and structure of the MnO۲/CNSs@PPy nanocomposite were characterized using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), nitrogen absorption by the Brunauer-Emmett-Teller (BET) method, dynamic light scattering (DLS) size distribution, and Fourier-transform infrared spectrometry (FT-IR). The INCAT tool was coupled with GC-FID and applied for dynamic headspace perconcentration and determination of linear alkyl benzenes (LABs) in wastewater samples. Optimization of the main effective experimental variables of the proposed method was carried out using a central composite design (CCD) based on response surface methodology (RSM). Under the optimal conditions, the limits of detection (LODs) and limits of quantification (LOQs) were ۰.۵-۱.۰ and ۱۰-۱۵ ng mL-۱, respectively, and the calibration plots were linear over the range of ۰.۰۱۵–۱۰ μg mL-۱.The relative standard deviations (RSDs%) for intra-day, inter-day, and inter-INCAT precision were calculated to be ۶.۵, ۱۱.۷, and ۱۵.۲%, respectively. The developed technique was employed successfully for the extraction and determination of LABs in water and wastewater samples with average recovery values ranging from ۹۲-۱۰۹%. The superiority of the adsorbent for separation and preconcentration of LABs was demonstrated by its comparison with other INCAT tools. A single INCAT device was used more than ۹۰ times without significant change in its extraction capability.